


Destructive Interference

by gigiree



Category: Undertale (Video Game)
Genre: Anti Soulmates AU, F/M, Medium Burn, post pacifist run
Language: English
Status: In-Progress
Published: 2019-03-14
Updated: 2019-03-14
Packaged: 2019-11-18 03:43:52
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,204
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18112592
Author URL: https://archiveofourown.org/users/gigiree/pseuds/gigiree
Summary: You physically can’t stand being near him. It hurts. Despite it all, you’re still you. Stubborn and Inflexible when it comes to your loved ones.No matter how much it hurts, no matter how much your very self rebels, you’ll keep on reaching out for him. You wonder if he’ll do the same.





	Destructive Interference

Part 1. Out of Phase

 

 **InsertUsernameHere:** Dude! That would be awesome if we could actually meet up one of these days! I’m still unpacking my stuff, but like seriously, show me around. I’m free after work around 6 pm?

 

 **Hotdogdays:** lol. your schedule never seems to match mine. it’s ok. we’ll eventually figure it out. i start my night shifts at 6. i’m surprised you’re still awake right now anyway.

 

 **InsertUsernameHere: -_-** same time zone now, bonehead.

 

 **Hotdogdays:** if i were you, i’d use that beautiful built in excuse ya got there.

 

 **InsertUsernameHere:**????

 

 **Hotdogdays:** sweet sweet jet lag. no one would question you sleeping a lil’ extra at all.

 

 **InsertUsernameHere: plz.** You never need an excuse. and I still need to unpack a few stuff.

 

 **Hotdogdays:** zzzzzzzzz

 

 **InsertUsernameHere:** alright. I’ll let you sleep now, lazy. I’m gonna be responsible and clean up my room.

 

 **Hotdogdays:** eww.

 

You grin stupidly at your phone, laughter blooming against your tightly pressed mouth as you waste time messaging your long time internet friend.

 

The moon outside your bedroom window is already arcing towards her zenith. The few stars bright enough to make themselves seen beyond all the city lights looks friendly, and give you the distinct feeling that they’re encouraging you to keep having fun.

 

Instead you decide to be an adult and follow through.

 

 **InsertUsernameHere:** GOODNIGHT SANS!

 

 **Hotdogdays:** goodnight, you.

 

You swipe off the blogging app, and move on to your music, selecting your “Get Shit Done” Playlist before your tackle the horde of boxes currently conquering the new bed you’d purchased off of Craigslist. The drifting notes of an acoustic guitar fill the small space, making even the messy piles of clothes feel homey.

 

You’ll have to thank Sans for the song recommendations later. You have a lot to thank Sans for, actually. He’d come into your life just when you’d needed a stranger’s kinship. The kind of trust shared between two people who don’t know each other but who’ll tell each other their woes because they know they’ll never have to face the other person again.

 

Sans had offered that when he’d given you some sage advice under a venting post you’d made during work.

 

It became sort of a strange dynamic after that. You’d post something, be it your occasional art pieces or a funny dream, and without fail, his reply would be first in all your notifications. His stupid hot dog icon seemingly waving at you with alacrity.

 

Public replies had become sporadic private messaging. Private messaging has devolved into a strange, welcome friendship.

 

The funny thing is, being on at the same time is a rare thing for you two. Your schedules had just never seemed to coincide, and even having finally moved to the same time zone, you’re finding it difficult to plan your first in-person meeting.

 

Things in your life are finally falling into place. It would be nice if Sans somehow did too.

—

 

You two finally decide on a time and date. You dismiss your students from the lab fifteen minutes early. You frame it as a kindness for them, considering it’s only the first day of the semester.

 

But you know deep deep down in that orange Soul of yours that it’s because you want to look extra nice for your meeting today. You want those extra fifteen minutes to fluff up your hair and make sure your shirt is tucked into your high-waisted jeans. You’d even worn your cutest pair of boots today. The ones with the little heels and too many zippers.

 

They make the cutest clicking noise against the pavement as you make your way down to the novelty cafe you’d both agreed upon.

 

Your nerves have seemingly brought your intestines to life, making it feel like they’ve wriggled around each other and tied themselves into knots the closer the cafe gets. Your grin becomes shaky, and chilled sweat beads your forehead. You hold your phone tight in your hand, ignoring the twinge that springs up at the base of your neck.

 

You’re just a little anxious, that’s all.

——

 

He’s just a little anxious, that’s all.

 

He keeps mopping up the sweat that beads over his zygomatic arches and at his temples. Stars know how he’s managed to work himself up into a tizzy, but he thinks if he had a stomach right now, it would be roiling.

 

It’s just so rare for him to jive with another person like he does you. Your communication has only ever been through text and the occasional video chat, but it had been effortless. As easy as the stars falling into place on the horizon and the wheeling of the moon through the sky.

 

He’d finally managed to find a spot between his multiple odd jobs, just for you. He’d specifically closed his hot dog stand two hours early, lost out on potential profit, because he’s been wanting to meet you for so long.

 

You’re finally on the same coast as him. He’s scared it won’t be the same. That the banter and the jokes will fall flat in the space between you two.

 

Hell, he’d even dressed sort of nice for today. He’d worn jeans for once and his nice sneakers with the metal stars for aglets at the end of the laces.

 

He hopes it’s worth the effort.

—-

 

God. He’s just as cute in person. He’s got the goofy grin edging into his eye sockets, the lights in them winking bright like the stars that had welcomed you to the city last night.

 

The light drifting through the cafe paints him in gentle shades, the creamy white of his skull is just as welcoming as the blue of his jacket.

 

Slowly, slowly you close the distance between you and he. Slowly, slowly the twinge at the base of your neck crawls up your spine.

 

“hey.” He smiles, and his rolling voice makes your guts do another spin cycle.

 

“Hey.” You grin back, but you feel something strange bubble your throat as you do.

 

His hand closes around yours in a handshake and several things happen.

 

One, the pain in your neck blooms forth into a full blown, sudden migraine. Searing, prickling agony that buzzed down to where your skin meets his bone.

 

Two, there’s a loud flatulence noise as Sans yelps in pain.

 

Three, you throw up on his nice new shoes.

 

You can barely eke out your apologies beyond your tears of embarrassment, and before he can say anything, you run into the bathroom. The door slams behind you, seemingly mocking your circumstance.

—-

He still feels the ghost of pain lancing up his radius, but he’s more so aware of the stares he’s getting from the other cafe patrons.

 

There’s human vomit on his nice new shoes, but he shakily sweeps that up with some blue magic, and slides it with disgust into an empty cup on the table.

 

He shudders and looks at his audience, shrugging.

 

“guess i was barfing up the wrong tree by coming here.”

 

That gets a few chuckles and everyone goes back to normal. He decides to check on you.

—-

 

When he finally manages to get you to come out of the bathroom, your tears of mortification finally dried up, he’s not sure where to begin.

 

He’s aware of the volatile sparks of magic now flickering at the edge of his eye sockets. He’s aware of the paranoia threatening to chew on his logic until his words drip with unfounded accusations.

 

He doesn’t want that. All he’d wanted was an outing with a friend.

 

But as it stands, he can’t stand being near this friend. Physically.

 

And by the looks of you, he thinks the same thing’s happening to you.

 

He’s not sure why. He’s not sure how. But he’s curious now, and if there’s anything worth putting effort into, it’s finding things out.

 

He doesn’t extend his hand to you. He doesn’t offer a short cut. But he gives you a smile he hopes looks confident.

 

“Sorry about your shoes again.” You say for the third time now. You blood-shot eyes and timid smile soften his feelings. He is reminded that you are his cross-country, humor at 2AM, star-loving friend. You give another little sniff to clear your tears.

 

“snot your fault kiddo. guess my whoopee cushion in the hand trick doesn’t have a 100 percent success rate. anyway, i think I know somewhere we can get answers.”

 

He’s actually surprised when you giggle a little, wipe your nose with a tissue, and agree to go with him.

 

And if he’s not wrong, he’d say you looked just as curious too.

—-

 

“F-fascinating. This I-is incredible.” Dr. Alphys says, her spectacles gleaming in the cold, fluorescent light of the hospital room.

 

You sit uncomfortably on the examination table, a hand placed hesitantly over your chest where you can imagine your Soul beats thinly. Vulnerability laces through your body, and you find yourself hunching over a bit more. The room would feel probably feel colder and too clinical if you weren't a grad student used to this sort of environment. But you are. It's more Alphys' enthusiasm than anything that makes you nervous.

This is your first time meeting her. Your first time meeting someone who happens to be a good friend of Sans, and it’s because there’s something potentially very, very wrong with your Soul.

 

Sans is slumped in the corner of the room, crossing his arms over his chest in a way that tells you he’s not entirely trusting right now.

 

You don’t blame him. You’re feeling particularly naked after having your Soul scanned.

 

Dr. Alphys turns her large computer screen in your direction. You squint as you make out what looks like several sine waves on the screen. You’re unsure what to make of it.

 

“What does it mean?”

 

To your surprise, it’s Sans who answers.

 

“our Soul frequencies are completely out of phase.”

 

He sounds bitter, tired. The edge of humor in his tone is darkly colored, and you want nothing more than to comfort him.

 

You’re scared though. You’ve never liked pain. It breaks you in the most delicate ways. Alphys seems to take your silence for confusion, and explains gently.

 

“Perfectly out of phase. Every time your Soul’s frequency rises, his falls. They’re perfectly opposite. I’ve never seen this before. M-my theory is that your Souls are repelling each other in whichever way possible as a self-defense mechanism.”

 

You somehow manage to eke out a question.

 

“Self-defense? We’re not...a danger to each other? Are we?”

 

Alphys looks a bit sympathetic as she pulls up the chart again. You see it this time. Where your frequency dips, his crests. Vice Versa. Your mind dredges up a long forgotten fact from one of your undergraduate physics classes. The ones you took just because it was a requirement and not because you had any real interest in the subject.

 

If two waves that are perfectly out of phase meet, they cancel each other out. Destructive Interference, it was called. It all clicks then.

 

You don’t know what possesses you to say it, but you do.

 

“I take it this is a _sine_ that we weren’t really meant to meet up today, right?”

 

You look at Sans and he looks at you, and the absurdity of it all causes you two to burst into fits of laughter.

 

Dr. Alphys isn’t sure what to make of it all.

 

Do be fair, neither are you.

—-

 

“tori says it’s something like anti Soulmates.”

 

“A WHAT?!”

 

“yeh. it’s not...it doesn’t usually happen.” He says from across the table.

 

“Leave it to us to find our anti Soulmate.” You laugh incredulously.

 

“leave it to us to still force a meet-up even when our timing was always wrong.”

 

It’s slightly off-putting how far he’s chosen to sit from you for lunch, but you can’t say your not relieved. As it is, the nausea is still there today but you managed it with some pills before coming here.

 

You frown, hiding your expression in the lip of your mug as you take a swig of coffee. The bitterness washes away the bile at the back of your throat and you feel a little better as you stare at him.

 

“Are you sure you still want to...I mean we don’t really have to meet up in person anymore if it’s causing you discomfort?”

 

He sets down his phone, fully looking at you as best as he can from across the long edge of the table.

 

“you’re my friend.”

 

He says it so matter-of-fact. Like it wouldn’t have made a difference even if your very presence could turn him into a snail. He’s accepted this so well.

 

You feel a rush of affection for him, and try and hide your flush by taking another sip of coffee.

 

You miss because you’re so distracted and drop some down your shirt. You almost want to cry when you notice the napkin holder is all the way on his side.

 

He gives you a mocking grin, before sliding it over you way, being careful not to touch you at all.

 

You decide he’s worth the effort. You just hope you can make this all fall into place somehow.

**Author's Note:**

> Welcome to the anti Soulmate Au. This is gonna be a considerably shorter story than JE :)


End file.
